(RxWiki News) The majority of breast cancers are fed by the hormones estrogen and progesterone. That’s why women with hormone-sensitive breast cancer are prescribed medicines to block these hormones. But a good portion of women may be skipping the therapy.
Some 26 percent of women either did not start or stopped taking the recommended five-year course of hormone-blocking therapies, according to a new study. These medications, taken daily in pill form, are designed to keep breast cancer from returning and extend survival.
The women either did not know the importance of the therapy or quit because the side effects were too unpleasant.
Recent studies have suggested that 10 years of hormone therapy may be even more effective than five years. So the gap among women not using these medications needs to be addressed with better education, according to the authors.
"Understand the medications you are prescribed."
Researchers at the University of Michigan Comprehensive Cancer Center, led by Christopher Friese, PhD, RN, assistant professor at the University of Michigan School of Nursing, looked at endocrine (hormone) therapy compliance and non-compliance.
Tamoxifen is given to women who have not yet gone through menopause. Medicines called “aromatase inhibitors” are given to post-menopausal women. Aromatase inhibitors are sold under such brand names as Arimidex (anastrozole), Aromasin (exemestane) and Femara (letrozole).
Participants were identified through the Surveillance, Epidemiology and End Results, or SEER, tumor registries. The women were surveyed about their use of hormone-blocking therapy nine months after their breast cancer diagnosis and again some four years later.
The study involving some 750 breast cancer survivors found that 11 percent of participants never started the treatments and 15 percent quit the therapy.
"This highlights a concern many of us have had. Even though a drug may be of benefit, women have to take it as directed for the full benefit. Compliance is a serious issue," Adam Brufsky, MD, PhD, professor of medicine at the University of Pittsburgh School of Medicine, told dailyRx News.
Side effects were the most common reason cited for not starting or stopping the medications. Tamoxifen can cause menopausal symptoms such as hot flashes and vaginal dryness. Aromatase inhibitors can cause joint pain and weaken the bones.
Researchers found that women who received less information about the therapy were less likely to start taking the pills. The authors suggested this may be an opportunity for additional education.
Also, women who went to a surgeon versus a medical oncologist for follow-up visits were also less likely to start the therapy.
Women who were most worried about the cancer returning were most likely to follow the regimen, as were women who already took other medications.
“If guidelines begin to shift so that some women at high risk of breast cancer recurring need 10 years of endocrine therapy, then the number of women who persist with treatment will likely worsen. We need to develop better ways of supporting women through this therapy,” Dr. Friese said in a press release.
“Enhanced patient education about potential side effects and the effectiveness of adjuvant endocrine therapy in improving outcomes may improve initiation and persistence rates and optimize breast cancer survival,” the authors concluded.
Senior study author, Jennifer J. Griggs, MD, MPH, professor of internal medicine at the U-M Medical School and a medical oncologist who cares for women with breast cancer, added that creative educational approaches need to be developed. “This means providing better education about the importance of staying on these medications and partnering with primary care and cancer doctors to help patients manage symptoms,” Dr. Griggs said.
Findings from this study were published in the March issue of Breast Cancer Research and Treatment. Funding came from National Cancer Institute; National Institute for Nursing Research, and the American Cancer Society. There were no conflict of interest disclosures.